class Rubytracer::PointLight

Public Class Methods

new(value, point) click to toggle source
# File lib/rubytracer/lights/point.rb, line 5
def initialize(value, point)
  @value = value
  @point = point
end

Public Instance Methods

check_shadow(point, direction, distance, scene) click to toggle source
# File lib/rubytracer/lights/point.rb, line 10
def check_shadow(point, direction, distance, scene)
  ray = Geom3d::Ray.new(point + direction * 0.00001, direction)
  obj, alpha = scene.intersect(ray)
  pos = ray.pos(alpha)
  alpha < distance
end
diffuse(normal, point, scene) click to toggle source
# File lib/rubytracer/lights/point.rb, line 34
def diffuse(normal, point, scene)
  vector = @point - point
  dir = vector.unit
  dis = vector.length

  if check_shadow(point, dir, dis, scene)
    Colour.new(0,0,0)
  else
    @value * distance_loss(dis) * [0, dir.dot(normal)].max
  end
end
distance_loss(distance) click to toggle source
# File lib/rubytracer/lights/point.rb, line 17
def distance_loss(distance)
  ([0, 8 - distance].max / 8) ** 3
end
specular(normal, view_vector, point, scene) click to toggle source
# File lib/rubytracer/lights/point.rb, line 21
def specular(normal, view_vector, point, scene)
  vector = @point - point
  dir = vector.unit
  dis = vector.length

  if check_shadow(point, dir, dis, scene)
    Colour.new(0,0,0)
  else
    d = (2 * view_vector.dot(normal) * normal - view_vector).unit
    @value * distance_loss(dis) * [0, d.dot(dir)].max
  end
end